High heat to build toward Pioneer Day with storms lingering in the south and mountains

SALT LAKE CITY ( ABC4 ) – Happy Tuesday, Utah! High pressure is still in charge of the weather story in the west, and that means we will see building heat and the chance of storms in southern Utah and tied to the higher terrain.

Bottom Line? High pressure to the southwest brings high heat and monsoonal thunderstorms to parts of the Beehive State.

This area of high pressure, which retrograded west over the weekend, is slowly moving east again and will center up over Utah, Arizona, and Nevada by the midweek. Expect daytime highs to be about five degrees warmer than usual for this time of year. Daytime highs will climb into the upper 90s to the low 100s, with Salt Lake City going for its 13th triple-digit day of the summer today with a high of 101.

St. George will stay hot, with temperatures around 106 degrees, but any passing storms could rapidly cool temperatures, which we saw happen Monday evening.

With lingering moisture in Southern Utah, we see another afternoon and evening of scattered thunderstorms, some potential for flash flooding. Most of the moisture will hit south-central and southwest Utah, especially in higher terrain. These storms could easily roll into adjacent valleys and wherever we tap into heavy rain, we could see cause flash floods in lower spots like slot canyons, dry washes, and creeks.

Flash flooding is a possibility in some of our outdoor recreation areas in southern Utah including Zion National Park, Bryce Canyon, Grand Staircase, the San Rafael Swell, and Capitol Reef National Park.

The Wasatch Front will continue with hot conditions and hazy skies. Regional wildfire smoke continues to plague the state and at times, visibility along the Wasatch Front. While we expect sunshine, this smoke, combined with elevated ozone levels from the heat, will make the air quality in Salt Lake and Utah Counties “Unhealthy for Sensitive Groups,” with moderate air quality expected for the rest of Northern and Southern Utah where air quality is monitored.

As the core of high pressure nears Utah again, we will see temperatures climb. Peak heating is expected on Pioneer Day, with highs climbing eight to 10 degrees above seasonal norms in the south and about three to five degrees above average in the south.  In southern Utah, monsoonal moisture and thunderstorms will keep temperatures more consistent.

Pioneer Day will bring the threat of storms to St. George and a high of 107 degrees while Salt Lake City will top out at 104 degrees! The high heat for the holiday has prompted the National Weather Service to issue a “Heat Advisory” for the Wasatch Front, Great Salt Lake Desert and Mountains, Tooele and Rush Valleys, Cache Valley/Utah Portion, and Eastern

Juab/Millard Counties. The advisory goes into effect at noon on Pioneer Day and holds on until 10pm.  While many Utahns are excited to take part in the festivities, but it’s important to take extra precautions when outside and wear lightweight and loose-fitting clothing.

A weather pattern change is brewing for later in the work week, following the holiday. A cooler storm system will track inland from the Pacific Northwest and that will allow for temps to ease back to average along the Wasatch Front.  This change will also bring back the chance of thunderstorms and showers to Northern Utah with increasing moisture Thursday and into Friday before drier conditions ahead of the weekend.

We’ll keep you posted on the latest updates in our 4Warn Weather forecast both on-air and online, we are Good4Utah!

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